OK So this problem has bothered me every so often since 1997 in my 2G DSM and has continued through today with my VIII. It's strange because the only thing they have in common is the 4G63.

So, about once a month, I'll be driving at low RPM, gun it, and there is simply NO power (usually between 3K and 4K rpm) but the boost rockets up faster than ever! I'll be hitting the boost limiter on my EBC which is 1.6 bar! The lack of acceleration at full throttle continues until I let off the gas, then press it again, after which the power instantly comes back. Anyone have this problem? It has been with me since my Eclipse was bone stock through all states of tune up to a turbo upgrade, and from my Evo totally stock to mildly modified. It's the strangest thing. It doesn't happen enough to bother me normally, but it happened today when I REALLY needed to get on the freeway and blipping the throttle off and on didn't exactly help me merge. I did a search, but wasn't quite sure what to search for. I'm pretty sure there is nothing mechanically wrong with my car, and the fact that both of these 4G63 cars had the same problem leads me to believe it's a gremlin in the ECU somewhere.

This is one theory I thought of recently: Some amount of knock is being detected, so the ECU is switching to the knock map, which pulls timing and floods the motor with fuel. The un-burnt fuel is then getting into the exhaust manifold and exploding, hence the higher than normal boost because that is effectively what an anti-lag system does. Now, with explosions in the exhaust manifold, the knock sensor senses MORE knock and keeps timing pulled and keeps flooding fuel, so the cycle continues. Then when I lift off the gas, the knock goes away, and all is well again. Problem is, I don't know how fast the ECU switches maps. Does this theory make any sense? If not, any ideas?

TIA

 

Wow, nobody? A friend of mine was telling me he guns it when it's cold and it "pulls boost", which I found odd considering he has an aftermarket boost controller. Thought maybe this was the same thing as I'm experiencing, since I've never really goosed it with it cold. So, I figured I'd have a go when it was cold and see what he's talking about. One thing's for sure, it DIDN'T PULL BOOST at all, it built it faster than normal and hit the boost limiter on my controller at a very low RPM with it beeping at me telling me it's limiting boost (which never happens on channel 3 of 4 in my EBC). It hit so hard, in fact, the EBC couldn't keep up and it hit fuel cut at a max 1.63 bar (ultimate limit is set to 1.58 and introduces a 50% duty cycle increase in wastegate signal at that point) and it NEVER hits that high, not even on channel 4 will it normally do that). So, anyone have any idea what this is? It's the same thing I'm experiencing about every month or so, ever since new, and ever since I bought my DSM almost new. What map does the VIII use when it's cold? Is it different than the knock map? Has anyone ever heard of the car switching to whatever map it uses during a cold start after it's warmed up? I'm not very familiar with ECU tuning, so if anyone has any knowledge of this, it would be helpful. And, most importantly, how do you fix it (if possible)?

 

Sounds like your ECU is pulling timing which should reset itself when you lift off the gas and stomp on it again. Either turn down the boost or have someone drop the timing for you with a tune .

In any case if you can log the mishaps do so.